Estudo genético de períodos parciais de produção de ovos em codornas de corte

• Ano de defesa: 2010
• Autor(a) principal: Ribeiro, Jeferson Corrêa
• Orientador(a): Torres, Robledo de Almeida
• Banca de defesa: Carneiro, Antônio Policarpo Souza , Barreto, Sérgio Luiz de Toledo , Souza, Gustavo Henrique de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Coturnix coturnix; Massa de ovos; Períodos parciais; Peso de ovos; Produção de ovos
• Palavras-chave em Inglês: Coturnix coturnix; Egg mass; Partial periods; Egg weight; Egg production
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4744

The objective of this study was to estimate genetic and phenotypic parameters for egg production and egg mass in meat-type quails and to propose an optimal age for selection of meat-type quails through egg production and egg mass ratio. The data used for this study came from 3.503 female meat-type quails, (UFV1: 1.811 quails; UFV2: 1.692 quails) of the Breeding Program for Poultry, at Federal University of Viçosa. Laying was assessed by the number of eggs produced from the 42th day of life on. For the study on egg production, the traits analyzed were: partial periods of egg production until 77 days (N77), 112 days (N112), 147 days (N147), 182 days (N182) and total production period of 407 days (N407) through the use of a single and bi-trait animal model. For the study on egg mass, the characteristics analyzed were: egg mass in partial periods until 77 days (M77), 112 days (M112), 147 days (M147), 182 days (M182), and egg mass in the total period of 407 days (M407). To analyze the efficiency of selection in each partial period, in relation to the total period, it was used the relative efficiency. For the egg production trait, considering the genetic group UFV1, heritability for N77, N112, N147, N182 and N407 were 0.03, 0.06, 0.07, 0.08, and 0.16, respectively. The estimate of genetic correlation was higher between N112 and N407 (0.64). For other partial periods (N77xN407, and N147xN407 N182xN407), the values of genetic correlation ranged from 0.34 to 0.49. For the genetic group UFV2, the heritabilities for N77, N112, N147, N182 and N407 were, respectively, 0.20, 0.23, 0.25, 0.25, and 0.22. The correlation between each partial period with the total period presented median values ranging from 0.44 to 0.47. The relative efficiency for both genetic groups did not exceed the unity. The highest value found for the genetic group UFV1 was 0.4 during the period N112. For the genetic group UFV2, the highest relative efficiency was 0.49 for the periods N147 and N182. Considering the trait egg mass, the genetic group UFV1 obtained heritability values equal to 0.58 (M77), 0.59 (M112), 0.57 (M147), 0.59 (M182) and 0.24 (M407 ). The values for genetic correlations were medium, ranging from 0.51 (M77xM407) to 0.61 (M112xM407, M147xM407). For the genetic group UFV2, the heritabilities were of low magnitude: 0.05 (M77), 0.03 (M112), 0.04 (M147), 0.05 (M182) and 0.11 (M407). The values for genetic correlation ranged from 0.61 (M112xM407) to 0.93 (M77xM407). The highest relative efficiency value (0.96) was found during the period M112, to the genetic group UFV1, and 0.62 in the period M77 to the genetic group UFV2. Thus, the partial periods for egg production would be important to assist in the selection of meat-type quails, but the selection would be more efficient considering the total production. However, the use of selection through the mass of eggs until 112 days would be particularly interesting for genetic group UFV1, because the efficiency was close to the unity and the generation interval would be greatly reduced. For the group UFV2, even if it has presented low values of relative efficiency, it would only benefit from the reduction in generation interval for selection through the mass of eggs in the partial period until 77 days because it would allow three generations per year.